Core samples remain a valuable part of the oil and gas research process. Typically comprised of a cylindrical section of naturally occurring material, core samples are procured through the use of special drills that drill down into rock or sediment. A hollow steel tube referred to as a core drill is utilized. Once the core sample is obtained, it can then be compared to a variety of different core samples already in existence to examine the various media under varying conditions. More core samples continue to be catalogued on a regular basis, thus providing lab personnel with the ability to analyze new samples with even greater accuracy.
Throughout the coring process, samples are typically pushed into a tube and remain fairly intact. Once at the laboratory, the sample can then be removed from the tube so that it can be further inspected and analyzed using different types of equipment and techniques based on the type of data that is needed. The type of data required for oil and gas research can vary, but in most instances, it is vital to learn as much as possible about the permeability of the sample for drilling purposes as well as the type and amount of hydrocarbons that may be contained in the sample.
The composition of relevant subject materials can range from extremely strong materials to almost liquid materials. Core samples are typically taken with a long axis positioned parallel to the borehole’s axis, but it is also possible to retrieve core samples from the wall of a borehole that is already in existence.
It is also common practice to slab core samples. This refers to cutting the sample into multiple samples on a longitudinal basis. Custom stone cutting is a high precise skill that is often used early in the lab processing so that one set of samples can be archived early in the analysis to serve as a type of protection against any potential processing errors. One set of slabs may also be retained by the primary client while the second set of slabs will be delivered to a lab. Slabbing also presents a number of other benefits, including the ability to produce a smooth, flat surface for testing and examination of permeability, a characteristic that is relevant to oil and gas research.
Historically, core samples have proven to be highly important to the oil and gas industry, particularly in regards to determining the potential for a new well as well as the accessibility of a reservoir. The development of new technologies has made it increasingly easier to tap into resources contained in wells that were once deemed inaccessible. BP, for example, once estimated that only 40 percent of the oil in Prudhoe Bay in Alaska could be recovered. Later, BP revised those estimates to 60 percent. As new technologies continue to be developed, making it possible for oil and gas producers to recover even higher levels of resources, core samples for the purposes of oil and gas research will continue to play an important role.